Coating composition containing beads of high refractive index

ABSTRACT

The present invention is directed to a coating composition for print media. The present invention is further directed to improved printed substrates having the coating composition thereon and methods of making the improved print substrates. The improved print substrates substantially enhance the brightness and brilliance of colorants applied to the coating composition, especially compared to colorants applied to conventional coated or uncoated print media.

This application claims benefit of Ser. No. 60/071,944 filed Jan. 20,1998.

TECHNICAL FIELD

The present invention is directed to a coating composition for printmedia. The present invention is further directed to improved printsubstrates having the coating composition thereon and methods of makingthe improved print substrates. The improved print substratessubstantially enhance the brightness and brilliance of colorants appliedto the coating composition, especially compared to colorants applied toconventional coated or uncoated print media.

BACKGROUND OF THE INVENTION

The influence of a substrate on colorant brightness and brilliance canbe extremely important. Conventional print substrates typically containfiller materials and/or surface coatings in order to improve thebrightness and brilliance of colorants applied thereto. Although manyattempts have been made to enhance the brightness and brilliance ofcolorants, the attempts have resulted in less than acceptable colorquality.

There exists a need for methods and compositions, which are capable ofenhancing the brightness and brilliance of a wide variety of colorants,especially magenta colorants. There also exists a need for improvedsubstrates, which are providing superior, color quality by enhancing thebrightness and brilliance of colorants applied thereto.

SUMMARY OF THE INVENTION

The present invention addresses the needs described above by providing acoating composition and an improved print substrate coated with thecomposition. The coating composition contains unique microspheres havinga refractive index of from about 1.9 to about 2.4. Colorants applied tothe improved print substrate exhibit exceptional brightness andbrilliance compared to conventional print substrates. In addition, thepresent invention provides a coating that is elastic and does not causethe substrate to curl when heat is applied.

The present invention is also directed to methods of making thecomposition and improved substrates described above. Superior colorquality, print vibrancy, and colorant brilliance is achieved bycombining the aforementioned improved substrates and any colorantcomposition, particularly ink jet inks.

These and other features and advantages of the present invention willbecome apparent after a review of the following detailed description ofthe disclosed embodiments.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to a coating composition for printmedia. The present invention is also directed to improved printsubstrates comprising a base layer and the above coating composition onat least one surface of the base layer. The improved substratessubstantially enhance the brightness and brilliant of colorants appliedto the coating composition on the substrate, especially compared tocolorants applied to conventional coated or uncoated print media. Thepresent invention is further directed to improved print substrateshaving the above coating composition thereon and methods of making theimproved print substrates.

The coating composition of the present invention comprises microspheres,or beads, having a refractive index of from about 1.9 to about 2.4. Thebeads are available from The Photographic Institute, Beijing, China, andcomprise significant amounts (greater than about 1.0 weight percent) oftitanium, barium, calcium and oxygen; minor amounts (less than about 1.0weight percent) of aluminum, iron, strontium, zinc, and zirconium; andpossibly minute amounts of sodium, tellurium, and other elements. Anelectron microprobe analysis of a bead sample reveals the following beadcomposition as shown in Table 1 below.

TABLE 1 Aluminum 442 ppm Boron <25 ppm Barium major ppm Beryllium <25ppm Calcium major ppm Cadmium <25 ppm Cobalt <25 ppm Chromium <25 ppmCopper <25 ppm Iron 124 ppm Gallium <25 ppm Magnesium <25 ppm Manganese<25 ppm Molybdenum <25 ppm Nickel <25 ppm Oxygen major ppm Phosphorus<25 ppm Lead <25 ppm Tin <25 ppm Strontium 2878 ppm Titanium major ppmVanadium <25 ppm Zinc 3523 ppm Zirconium 9641 ppm

The commercially available beads are desirably substantially sphericaland have particle diameters ranging from about 2 microns to about 45microns, although having a variety of sizes is not critical to thepresent invention. As used herein, the phrase “substantially spherical”is intended to encompass beads having a perfectly spherical shape, aswell as, beads having an imperfect spherical shape, such as wherein thebead length may be slightly larger or smaller than the bead breath. Inone embodiment of the present invention, the commercially availablebeads are mechanically separated into samples having relatively narrowparticle diameter ranges. For example, one sample comprises beads havinga particle diameter range of about 27 to about 45 microns. Anothersample comprises beads having a particle diameter range of about 2 toabout 43 microns. Coating compositions of the present invention may beprepared using commercially available beads or select beads having adesired particle size or particle size range.

Image analysis of two bead samples is given below. All units are inmicrons.

SAMPLE 1 1 Std Measurement Average Minimum Maximum Deviation Longest12.68 4.22 43.07 8.18 Dimension Breath 11.24 2.74 41.52 7.98 Area Equiv.11.69 3.58 42.18 8.03 Diameter

SAMPLE 2 1 Std Measurement Average Minimum Maximum Deviation Longest39.80 30.45 44.87 2.82 Dimension Breath 38.17 27.83 43.35 2.92 AreaEquiv. 38.53 28.58 43.75 2.85 Diameter

As shown by the above data, Sample 1 has a broad particle sizedistribution from about 1 to about 45 microns, while Sample 2 has a muchnarrower particle size distribution from about 25 to about 45 microns.In both samples, the equivalent circular diameter (area equivalentdiameter) is very close to the particle length and breath, indicatingthat the beads are almost perfectly spherical particles.

The coating composition of the present invention optionally furthercontains one or more polymeric binders. Suitable binder materialsinclude, but are not limited to, naturally-occurring polymers,synthetically-modified naturally-occurring polymers or syntheticpolymers as exemplified in Water-Soluble Polymers, C. L. McCormick, J.Bock, and D. N. Schulz, in Vol. 17, Encyclopedia of Polymer Science andEngineering, John Wiley and Sons, Publishers (1989), pgs. 730-84.Desirably, the binder comprises one or more of the following polymers:polyvinylpyrrolidone (PVP), polyvinylalcohol (PVOH), polyhydroxyethylacrylate, polyhydroxyethyl methacrylate, polyacrylamide,polymethacrylamide, polyethylene glycol, carboxymethyl cellulose, sodiumcarboxymethyl cellulose, hydroxypropyl cellulose, hydroxyethylcellulose, polyacrylic acid and polyacrylic acid salts, polymethacrylicacid and polymethacrylic acid salts, polyvinylsulfonate andpolyvinylsulfonate salts, poly-2-acrylamido-2-methylpropanesulfonic acidand poly-2-acrylamido-2-methylpropanesulfonic acid salts,polyacryloxytrimethylammonium chloride,polymethacryloxytrimethylammonium chloride, andpolydiallyldimethylammonium chloride. Desirably, the binder comprisessodium carboxymethyl cellulose, polyvinylpyrrolidone (PVP),polyvinylalcohol (PVOH) or a combination thereof. More desirably, thebinder comprises polyvinylalcohol (PVOH).

The coating composition may optionally contain one or morecyclodextrins. Suitable cyclodextrins include, but are not limited to,α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin, δ-cyclodextrin,hydroxypropyl β-cyclodextrin, hydroxyethyl β-cyclodextrin, hydroxyethylα cyclodextrin, carboxymethyl α cyclodextrin, carboxymethyl βcyclodextrin, carboxymethyl γ cyclodextrin, octyl succinated αcyclodextrin, octyl succinated β cyclodextrin, octyl succinated γcyclodextrin and sulfated β cyclodextrin and sulfated γ-cyclodextrin(Cerestar USA Incorporated, Hammond, Ind.). Desirably, the cyclodextrincomprises β-cyclodextrin (β-CD), γ-cyclodextrin (γ-CD), hydroxyethylβ-cyclodextrin (he-β-CD), hydroxypropyl β-cyclodextrin (hp-β-CD), or acombination thereof. More desirably, the cyclodextrin compriseshydroxyethyl β-cyclodextrin (he-β-CD).

In the present invention, the coating composition may contain from about1 to about 30 parts by weight (pbw) beads, from about 10 to about 50 pbwpolymeric binder, optionally from about 0 to about 300 pbw cyclodextrinand from about 100 to about 500 pbw water. In some embodiments, thecoating composition contains from about 5 to about 10 parts by weight(pbw) beads, from about 10 to about 20 pbw polymeric binder, optionallyfrom about 100 to about 200 pbw cyclodextrin and from about 100 to about300 pbw water. The coating composition may contain more beads; however,significant colorant brightness and brilliance results from as little as1 pbw beads.

In addition to the beads, polymeric binder and cyclodextrin, the coatingcomposition of the present invention may also contain additionalcomponents. Examples of such additional components include, but are notlimited to, charge carriers; stabilizers against thermal oxidation;viscoelastic properties modifiers; cross-linking agents; plasticizers;charge control additives such as a quaternary ammonium salt; flowcontrol additives such as hydrophobic silica, zinc stearate, calciumstearate, lithium stearate, polyvinylstearate, and polyethylene powders;fillers such as calcium carbonate, clay and talc; surfactants;detackifiers; chelating agents; and TINUVIN® compounds; among otheradditives used by those having ordinary skill in the art. Chargecarriers are well known to those having ordinary skill in the art andtypically are polymer-coated metal particles. Desirable surfactantsinclude, but are not limited to, C₁₂ to C₁₈ surfactants such as cetyltrimethyl ammonium chloride and carboxymethylamylose, and othersurfactants such as Triton X-100 and SURFYNOL® 420. TINUVIN® compoundsare a class of compounds produced by Ciba-Geigy Corporation, whichincludes benzophenones, benzotriazoles and hindered amines. DesirableTINUVIN® compounds include, but are not limited to,2-(2′-hydroxy-3′-sec-butyl-5′-tert-butylphenyl)-benzo-triazole,poly-(N-β-hydroxyethyl-2,2,6,6-tetramethyl-4-hydroxy-piperidyl succinateand 2-(2′-hydroxy-3′,5′-ditertbutylphenyl)-5-chloro-benzotriazole. Theidentities and amounts of such additional components in the coloredcomposition are well known to one of ordinary skill in the art.Typically, one or more of the above additives are present in the coatingcomposition in an amount of from about 1 to 14 weight percent based onthe total weight of the coating composition.

The coating composition may be applied to a variety of substrates toform improved print substrates of the present invention. Suitablesubstrates to which the coating composition may be applied include, butare not limited to, paper, wood, a wood product or composite, wovenfabric, nonwoven fabric, textile, plastic, glass, metal, foil or anyother substrate that would benefit from having a coating compositionthereon. Plastic substrates include, but are not limited to, a plasticfilm, a plastic nonwoven web, or a plastic woven web. A preferredsubstrate is paper. Any existing or future type of paper or paperproducts may be used in the present invention.

Examples of paper or paper products include, but not limited to,printing and writing papers, packaging and industrial papers,paperboard, and tissue papers. Examples of printing and writing papersinclude, but are not limited to the following: wood-free coated papers;wood-containing coated papers; wood-free uncoated papers such as bondand writing paper, envelopes, offset and opaque circular, carbonless,tablet, forms bond, ledger, mimeograph, and manifold, duplication, faxbase, thermal base, technical papers, supercalandered, and specialtypapers; uncoated wood-containing papers such as supercalandered,directory, specialty converting and publishing; bristols such as coatedbristols, uncoated bleached bristols, tag, coated tag papers, filefolders, and tabulating; and thin papers such as cigarette paper, biblepaper, lightweight paper, lightweight specialty, manifold, cotton fiberpapers, and specialty thin papers.

Examples of packaging and industrial papers include, but are not limitedto the following: breached Kraft paper such as grocers bags, shippingsacks, wrapping paper, and converting paper; unbleached Kraft paper suchas grocers bags, shipping sacks converting paper, wrapping paper, andenvelopes. Examples of paperboard include, but are not limited to thefollowing: containerboard such as unbleached linerboard, bleachedlinerboard, corrugated medium, and chip and filler board; foldingboxboard/folding cartonboard such as solid bleached sulfite, bleachedand unbleached bristols, coated recycled board, coated unbleached Kraft,milk, cup, plate and foodservice stock (coated or uncoated), and foldingboard; gypsum wallboard; and tube/can and drum paperboard. Examples oftissue papers include, but are not limited to, sanitary tissues such asbathroom tissue, facial tissue, napkins, toweling, wiper stock, andother sanitary tissue papers.

The base layer of the improved print substrate may comprise one or moreof the above-mentioned layers. Desirably, the base layer is a coated oruncoated fiber-containing substrate such as Photoglossy Base,Presentation Matte Photobase, and High Quality Matte papers andWetstrength Media; a film such as White Opaque Films (e.g. KIMDURA®,K-C), Clears Films (e.g. MELINEX®, ICI) Backlit Films, and Vinyl; or anonwoven such as TYVEK®. More desirably, the base layer is a coated oruncoated paper. Most desirably, the base layer is a coated papercomprising a cellulose sheet coated with a polymeric film, such aspolyethylene.

The coating composition is coated onto the base layer by anyconventional coating method including, but not limited to, rod coating,dip coating, spray coating, gravure coating, knife coating, slotcoating, and roller coating. Desirably, the coating composition isapplied to the base layer by a process wherein the coating compositionis transferred from a bath onto a roller which extends into the bath,and onto at least one surface of the base layer. Optionally, the same ora different coating may be provided on the same or an opposite side ofthe base layer. The coated base layer then passes under or over a rod,which meters excess coating from the base layer. Once coated, the baselayer is dried in a conventional oven or by any other means known tothose of ordinary skill in the art.

The amount of coating composition applied to a surface of the base layermay vary depending upon the type of base layer used and the applicationof the final product. For example, a base layer in the form of anuncoated paper may require more coating composition than a base layer inthe form of a coated paper or film due to the increased porosity of thebase layer. Desirably, the coating composition is applied to a baselayer to produce a coating weight of from about 3.0 to about 60.0 g/m²of base layer surface area. In some embodiments, the coating weight isfrom about 9.0 to about 23.0 g/m² of base layer surface area. In otherembodiments, the coating weight is from about 15.0 to about 20.0 g/m² ofbase layer surface area.

The thickness of the coating composition may also vary depending uponthe type of base layer used and the application of the final product.Desirably, the coating composition has a thickness of about 0.1 to about5.0 mil. In some embodiments, the coating composition has a thickness ofabout 0.5 to about 2.0 mil. In other embodiments, the coatingcomposition has a thickness of about 1.0 to about 1.5 mil.

The present invention is further described by the examples which follow.Such examples, however, are not to be construed as limiting in any wayeither the spirit or scope of the present invention. In the examples,all parts are parts by weight unless stated otherwise.

EXAMPLE 1 Preparation of Bead/PVOH Composition

A coating composition was formulated by mixing 0.1 g of beads having acomposition as shown in Table 1 above and 1.0 g of a 10% solution ofpolyvinylalcohol (PVOH) (AIRVOL® 523, Air Products). After stirring for5 minutes on a hot plate, the solution converted to an elasticrubber-like material. The material was capable of being stretchedapproximately 3 feet without breaking. The elastic material was coatedonto a sheet of paper and air dried.

Magenta ink was applied to the coated sheet. Magenta ink was alsoapplied to a second uncoated sheet or paper. The magenta ink on thecoated paper was noticeably brighter than the magenta ink on theuncoated paper.

COMPARATIVE EXAMPLE 2 Preparation of TiO₂/PVOH Composition

For comparison to the coating composition of Example 1, a coatingcomposition was formulated by mixing 0.1 g of TiO₂ powder (TITANDIOXIDP25, DEGUSSA) and 1.0 g of a 10% solution of polyvinylalcohol (PVOH)(AIRVOL® 523, Air Products). After stirring for 5 minutes on a hotplate, the solution thickened but did not result in an elasticrubber-like material.

EXAMPLE 3 Preparation of Bead/PVOH/Cyclodextrin Composition

A coating composition was formulated by mixing 0.1 g of beads, 1.0 g ofa 10% solution of polyvinylalcohol (AIRVOL® 523, Air Products), 1.0 g ofγ-cyclodextrin, γ-CD, (Cerestar) and 1.0 g of water. The components werestirred in a beaker at room temperature for five minutes, forming anelastic rubber-like material. A sample of the elastic material wasapplied with a No. 40 rod onto a sheet of glossy paper and dried to forma highly reflective coating having a textured surface.

EXAMPLE 4 Preparation of Bead/PVOH Composition

A coating composition was formulated by mixing 0.5 g of beads, 3.0 g ofa 10% solution of polyvinylalcohol (AIRVOL® 523, Air Products) and 1.0 gof water. The components were stirred in a beaker at room temperaturefor five minutes, forming an elastic rubber-like material. A sample ofthe elastic material was stored at room temperature for approximately 5minutes, forming a clear rubber material.

EXAMPLE 5 Preparation of Bead/PVOH/Cyclodextrin Composition

A coating composition was formulated by mixing 0.3 g of beads, 1.0 g ofa 10% solution of polyvinylalcohol (AIRVOL® 523, Air Products), 1.0 g ofγ-cyclodextrin, γ-CD, (Cerestar) and 1.0 g of water. The components werestirred in a beaker at room temperature for five minutes, forming anelastic rubber-like material. A sample of the elastic material wasstored at room temperature for approximately 10 minutes, forming a latexrubber material.

EXAMPLE 6 Preparation of Bead/PVOH/Cyclodextrin Composition

A coating composition was formulated by mixing 0.11 g of beads, 1.0 g ofa 10% solution of polyvinylalcohol (AIRVOL® 523, Air Products), 1.0 g ofhydroxyethyl β-cyclodextrin, he-β-CD, (Cerestar) and 1.0 g of water. ThePVOH, he-β-CD and water were stirred in a beaker at room temperature forfive minutes. The beads were added to the mixture, which was stirred forthree minutes and heated on a hot plate for five minutes. Upon cooling,the mixture formed a very elastic rubber-like material. A sample of theelastic material was applied with a No. 7 rod onto a sheet of glossypaper and dried to form a highly reflective coating having a smoothsurface.

EXAMPLE 7 Preparation of Bead/PVOH/Cyclodextrin Composition

A coating composition was formulated by mixing 0.05 g of beads, 1.0 g ofa 10% solution of polyvinylalcohol (AIRVOL® 523, Air Products), 2.0 g ofhydroxyethyl β-cyclodextrin, he-β-CD, (Cerestar) and 1.0 g of water. ThePVOH, he-β-CD and water were stirred in a beaker at room temperature forfive minutes. The beads were slowly added to the mixture, which wasstirred for three minutes and heated on a hot plate for five minutes.Upon cooling, the mixture thickened, but did not form an elasticrubber-like material having remarkable stretch, most likely due to thehigher concentration of cyclodextrin.

EXAMPLE 8 Preparation of Bead/PVOH/Cyclodextrin Composition

A coating composition was formulated by mixing 0.05 g of beads, 1.0 g ofa 10% solution of polyvinylalcohol (AIRVOL® 523, Air Products), 3.0 g ofhydroxyethyl β-cyclodextrin, he-β-CD, (Cerestar) and 1.0 g of water. ThePVOH, he-β-CD and water were stirred in a beaker at room temperature forfive minutes. The beads were slowly added to the mixture, which wasstirred for three minutes and heated on a hot plate for five minutes.Upon cooling, the mixture thickened and had less stretch than in Example7.

Having thus described the invention, numerous changes and modificationsthereof will be readily apparent to those having ordinary skill in theart, without departing from the spirit or scope of the invention.

What is claimed is:
 1. A coating composition comprising microsphereshaving a refractive index of about 1.9 to about 2.4, and one or morecyclodextrins.
 2. The coating composition of claim 1, wherein themicrospheres comprise titanium, barium, calcium and oxygen.
 3. Thecoating composition of claim 2, wherein the microspheres furthercomprise aluminum, iron, strontium, zinc, and zirconium.
 4. The coatingcomposition of claim 3, wherein the microspheres have the followingcomposition: Aluminum 442 ppm Boron <25 ppm Barium >10,000 ppm Beryllium<25 ppm Calcium >10,000 ppm Cadmium <25 ppm Cobalt <25 ppm Chromium <25ppm Copper <25 ppm Iron 124 ppm Gallium <25 ppm Magnesium <25 ppmManganese <25 ppm Molybdenum <25 ppm Nickel <25 ppm Oxygen >10,000 ppmPhosphorus <25 ppm Lead <25 ppm Tin <25 ppm Strontium 2878 ppmTitanium >10,000 ppm Vanadium <25 ppm Zinc 3523 ppm Zirconium 9641 ppm


5. The coating composition of claim 1, wherein the microspheres aresubstantially spherical and have particle diameters ranging from about 2microns to about 45 microns.
 6. The coating composition of claim 5,wherein the microspheres have particle diameters ranging from about 27to 45 microns.
 7. The coating composition of claim 5, wherein themicrospheres have particle diameters ranging from about 2 to 43 microns.8. The coating composition of claim 1, further comprising one or morepolymeric binders.
 9. The coating composition of claim 8, wherein theone or more polymeric binders comprise polyvinylpyrrolidone (PVP),polyvinylalcohol (PVOH), polyhydroxyethyl acrylate, polyhydroxyethylmethacrylate, polyacrylamide, polymethacrylamide, polyethylene glycol,carboxymethyl cellulose, sodium carboxymethyl cellulose, hydroxypropylcellulose, hydroxyethyl cellulose, polyacrylic acid, polyacrylic acidsalts, polymethacrylic acid, polymethacrylic acid salts,polyvinylsulfonate, polyvinylsulfonate salts,poly-2-acrylamido-2-methylpropanesulfonic acid,poly-2-acrylamido-2-methylpropanesulfonic acid salts,polyacryloxytrimethylammonium chloride,polymethacryloxytrimethylammonium chloride, polydiallyldimethylammoniumchloride, or combinations thereof.
 10. The coating composition of claim8, wherein the one or more polymeric binders comprise sodiumcarboxymethyl cellulose, polyvinylpyrrolidone (PVP), polyvinylalcohol(PVOH) or a combination thereof.
 11. The coating composition of claim 1,wherein the one or more cyclodextrins comprise α-cyclodextrin,β-cyclodextrin, γ-cyclodextrin, δ-cyclodextrin, hydroxypropylβ-cyclodextrin, hydroxyethyl β-cyclodextrin, hydroxyethyl αcyclodextrin, carboxymethyl α cyclodextrin, carboxymethyl βcyclodextrin, carboxymethyl γ cyclodextrin, octyl succinated αcyclodextrin, octyl succinated β cyclodextrin, octyl succinated γcyclodextrin, sulfated β cyclodextrin, sulfated γ-cyclodextrin, orcombinations thereof.
 12. The coating composition of claim 11, whereinthe one or more cyclodextrins comprise β-cyclodextrin, γ-cyclodextrin,hydroxyethyl β-cyclodextrin, hydroxypropyl β-cyclodextrin, or acombination thereof.
 13. The coating composition of claim 1, wherein thecomposition comprises from about 1 to about 30 parts by weight (pbw) ofthe microspheres, from about 10 to about 50 pbw of one or more polymericbinders, up to about 300 pbw of one or more cyclodextrins, and fromabout 100 to about 500 pbw water.
 14. The coating composition of claim13, wherein the composition comprises from about 5 to about 10 parts byweight (pbw) of the microspheres, from about 10 to about 20 pbw of oneor more polymeric binders, from about 100 to about 200 pbw of one ormore cyclodextrins, and from about 100 to about 300 pbw water.
 15. Asubstrate coated with the coating composition of claim
 1. 16. Thesubstrate of claim 15, wherein the substrate comprises paper, wood,woven fabric, nonwoven fabric, textile, plastic, glass, metal, foil, ora combination thereof.
 17. The substrate of claim 16, wherein thesubstrate comprises paper.
 18. The substrate of claim 15, wherein thecoating composition is applied to the substrate to produce a coatingweight of from about 3.0 to about 60.0 g/m².
 19. The substrate of claim18, wherein the coating composition is applied to the substrate toproduce a coating weight of from about 9.0 to about 23.0 g/m².
 20. Thesubstrate of claim 18, wherein the coating composition is applied to thesubstrate to produce a coating weight of from about 15.0 to about 20.0g/m².
 21. An article comprising: a substrate; and a coating compositionon a surface of the substrate; wherein the coating composition comprisesmicrospheres having a refractive index of about 1.9 to about 2.4, andone or more cyclodextrins.
 22. The article of claim 21, wherein thesubstrate comprises paper, wood, woven fabric, nonwoven fabric, textile,plastic, glass, metal, foil, or a combination thereof.
 23. The articleof claim 22, wherein the substrate comprises paper.
 24. The article ofclaim 21, wherein the coating composition is applied to the substrate toproduce a coating weight of from about 3.0 to about 60.0 g/m².
 25. Thearticle of claim 24, wherein the coating composition is applied to thesubstrate to produce a coating weight of from about 9.0 to about 23.0g/m².
 26. The article of claim 25, wherein the coating composition isapplied to the substrate to produce a coating weight of from about 15.0to about 20.0 g/m².
 27. The article of claim 21, wherein themicrospheres comprise titanium, barium, calcium and oxygen.
 28. Thearticle of claim 27, wherein the microspheres further comprise aluminum,iron, strontium, zinc, and zirconium.
 29. The article of claim 28,wherein the microspheres have the following composition: Aluminum 442ppm Boron <25 ppm Barium >10,000 ppm Beryllium <25 ppm Calcium >10,000ppm Cadmium <25 ppm Cobalt <25 ppm Chromium <25 ppm Copper <25 ppm Iron124 ppm Gallium <25 ppm Magnesium <25 ppm Manganese <25 ppm Molybdenum<25 ppm Nickel <25 ppm Oxygen >10,000 ppm Phosphorus <25 ppm Lead <25ppm Tin <25 ppm Strontium 2878 ppm Titanium >10,000 ppm Vanadium <25 ppmZinc 3523 ppm Zirconium 9641 ppm


30. The article of claim 21, wherein the microspheres are substantiallyspherical and have particle diameters ranging from about 2 microns toabout 45 microns.
 31. The article of claim 30, wherein the microsphereshave particle diameters ranging from about 2 to 45 microns.
 32. Thearticle of claim 30, wherein the microspheres have particle diametersranging from about 2 to 43 microns.
 33. The article of claim 1, whereinthe coating composition further comprises one or more polymeric binders.34. The article of claim 33, wherein the one or more polymeric binderscomprise polyvinylpyrrolidone (PVP), polyvinylalcohol (PVOH),polyhydroxyethyl acrylate, polyhydroxyethyl methacrylate,polyacrylamide, polymethacrylamide, polyethylene glycol, carboxymethylcellulose, sodium carboxymethyl cellulose, hydroxypropyl cellulose,hydroxyethyl cellulose, polyacrylic acid, polyacrylic acid salts,polymethacrylic acid, polymethacrylic acid salts, polyvinylsulfonate,polyvinylsulfonate salts, poly-2-acrylamido-2-methylpropanesulfonicacid, poly-2-acrylamido-2-methylpropanesulfonic acid salts,polyacryloxytrimethylammonium chloride,polymethacryloxytrimethylammonium chloride, polydiallyldimethylammoniumchloride, or combinations thereof.
 35. The article of claim 34, whereinthe one or more polymeric binders comprise sodium carboxymethylcellulose, polyvinylpyrrolidone (PVP), polyvinylalcohol (PVOH) or acombination thereof.
 36. The article of claim 21, wherein the one ormore cyclodextrins comprise α-cyclodextrin, β-cyclodextrin,γ-cyclodextrin, δ-cyclodextrin, hydroxypropyl β-cyclodextrin,hydroxyethyl β-cyclodextrin, hydroxyethyl α cyclodextrin, carboxymethylα cyclodextrin, carboxymethyl β cyclodextrin, carboxymethyl γcyclodextrin, octyl succinated α cyclodextrin, octyl succinated βcyclodextrin, octyl succinated γ cyclodextrin, sulfated β cyclodextrin,sulfated γ-cyclodextrin, or combinations thereof.
 37. The article ofclaim 36, wherein the one or more cyclodextrins comprise β-cyclodextrin,γ-cyclodextrin, hydroxyethyl β-cyclodextrin, hydroxypropylβ-cyclodextrin, or a combination thereof.
 38. The article of claim 21,wherein the coating composition comprises from about 1 to about 30 partsby weight (pbw) of the microspheres, from about 10 to about 50 pbw ofone or more polymeric binders, up to about 300 pbw of one or morecyclodextrins, and from about 100 to about 500 pbw water.
 39. Thearticle of claim 38, wherein the coating composition comprises fromabout 5 to about 10 parts by weight (pbw) of the microspheres, fromabout 10 to about 20 pbw of one or more polymeric binders, from about100 to about 200 pbw of one or more cyclodextrins, and from about 100 toabout 300 pbw water.
 40. A method of enhancing the brightness andbrilliance of a colorant, said method comprising: applying the colorantonto the coating composition of claim
 1. 41. A method of enhancing thebrightness and brilliance of a colorant, said method comprising:applying the colorant onto the coating composition of the article ofclaim 21.